Rheostat.



Patented Feb. l9, l90l.

N. H. sumzu.

an EOSTAT.

(Application filed June 29, 1899) (No Model.)

[Hit $25555 UNITED STATES PATENT OFFICE.

RH EOSTAT.

SPECIFICATION formingpart of Letters Patent N 0.

Application filed June 29, 1899- 668235, dated February 19, 1901. Serial No. 722,843. (No model.)

To all whont it ntay concern.-

Be it known that I, NATHAN H. SUREN, of Needham, county of Norfolk, and State of Massachusetts, have invented an Improvement in Rheostats, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to rheostats, and has for its object to construct a rheostat which may be of simple construction and adapted tobe easily operated and understood even by unskilled persons and by which a number of known variations in resistance may he made.

The invention consists in a number of resistance-coils, two series or sets of contacts preferably arranged in circular form, and a movable switch, one arm of which is insulated from the other and is adapted to cooperate with one series of contacts, while the other arm cooperates with the other series of contacts, and circuit -wires connecting said contacts with the resistance-coils and with one of the arms of the switch.

Figure 1 shows in plan view a rheostat embodying this invention, the resistance-coils and circuit-wires being represented in diagram. Fig. 2 is a detail of the two-armed switch, one of the arms of which is insulated from the other. Fig. 3 is a detail showing one of the single contacts, and Fig. 4 is a detail showing one of the double contacts.

(1 represents the t'wo arined switch, which isnnade as a flat bar or strip of metal provided at each end with a knob a, by which it may be turned on its pivot a and to the under side of said bar, at one side of the pivot a a contact-spring a is secured directly to the bar, which is in electrical connection with it, and at the opposite side of said pivot another contact-spring a is secured to insulated bushings fitted into holes in the bar, so

as to be insulated from the bar. Thus a twoarmed switch is produced, one arm of which is insulated from the other. that said two-armedswitch may be made in many different ways;. but the Way herein shown is simple and not liable to get out of order and in practice is very efficient.

A number of contaotstare arranged on the board A, preferably in circular form, as shown, they being disposed in two semicir- It is obviouscular series or sets B C, and, as herein shown,

some of said contacts are single contacts, as

contacts B (J are so that when the.

rest upon the lowermost contact of the other series. The series or set B comprises the following contacts, arranged in the order'described: single contact I), double contact I) I), double contact b 1), single contact b double contact b 12 double contact b b and double contact 19 6. The series or set comprises the following contacts, described: single contact 0, double contacts 0 c and single contacts 0 c c c 0". One of the circuit-terminals is connected to the pivotpost a of the switch and the other circuit- I terminal is connected to the single contact 0,

and normally the arms of the switch rest upon the single contacts I) and c, as shown in the drawings, and as no circuit-wire is connected to the contact b the current passes from the pivot-post a through one of theswitch-arms to the contact 0, and all of the' resistance-coils to be referred to will beshort circuited'.

Three resistance-coils d 01 OZ are'herein shown, each having a pair of terminals. 3 5

represent the terminals of the resistance-coild, and 7 9 the terminals of the resistance-coil arranged in the orderd, and 11 13 the terminals of the resistance- I coil (1 The circuit-wire 2 connects the pivotposta of the switch with the terminal3 of the resistance-coil d. A wire 4'connects the other terminal 5 of said resistance-coil'd with the contacts I) b b 19 A wire 6 connects the terminal 5 with the terminal 7 of the resistance-mild, and a wire 8 connects the terminal 9 of said resistancecoil d with the contacts 0 c c and b A wire 10 connects.one of the terminals 11 of the resistance-coil ol with the contacts b b 12, c, and 0 A wire 12 connects the other terminal 13 of said resistance-coil d with the contacts b b and c. The switch-arm normally rests upon the contacts b and c and is adapted to be moved into six dilferent positions-first, onto the contacts b b and c 0; second, onto the contacts b b and contact third, onto the contactsb and contact 0 fourth, onto the contacts I) b and contact c fifth, ontothe contacts b b and c and,

v for the current being aha, a and c.

sixth. onto the contacts Z1 Z9 and contact Thus the switch has in all seven differ-- ent positions, although so far as my invention is concerned it maybe arranged to have a greater or less. number, according to the" number of contacts provided.

By the arrangement of circuit-wires herein shown when the switch is in its first position, as shown in the drawings, all of the resistance-coils will be short-circuited, the path When in its second position, with the switch-arm resting on the double contacts 1) b and 0' 0 all of the resistance-coils will be connected in parallel with each other, and,'assun1ing each resistance-coil. to be of the same known resistance, one-ninth of the total resistance will be cut in. In said second position of the switch-arm a'thre'e paths for the current-will be established, one for each resistance-coil,

, asfollows: 0t 2 d 4 b a b 12 c and a a a o 10 d 12 c and a oc c 8 d 6 4 b a b 12 c. When the switch-arm a is in its second position, it will be seen that both double contacts I) bfand c c are brought into use, and the former receives upon it the pen qflwhich rests upon-both contacts, and the latter receives upon it the pen a which also rests upon both contacts, said pens (t a being made wide enough for the purpose; In the third position,

with the switch-arm resting on the single contact c and double contacts '63 1), two of the 1 resistance-coils d and d will be connected in parallel with each other and one-sixth of the total resistance will be cut in. In said third position of the switch-arm a the paths-for the currentwill be established as follows: a 2 d 4 b a b 12 sand at a c a 8d 6 4 b a b 12 c. 'In' the fourth position, with the switch-arm resting on the contacts 0 and b one of the. resistance-coils d will be connected in circuit and one-third of the total resistance cut in, it

- being understood that no circuit-wire c0nnects with the contact if. In said fourth position of the switch-arm a a-single path for' ance will be cut in. -In said fifth position of .the switch-arm a the paths for the current will be as follows: a 2 d 4 b a b 1O 01 -12 0 and a a a, c 8 d 6 to 4' and thence by b a In the fifth position, with b 10 d 12 to c. In the sixth position, with 6o c and b b, all of the resistance-coils will be connected in eries, andthereby the total resist-ance will be cut in, it being understoodv that no circuit-wire is connected to contact 0 In said'seventh position of the switch-arm a the path of the cu rrent will be established as follows: a 2 d 6 d 8 b a b 10 d? 12 c. I do.- not, however, desire to limit my invention to this particular arrangement of circuit-wires.-

As resistance-coils I have herei'n represented ordinary incandescent lamps of .a known resistance; but in lieu thereof any other form or construction of resistance-coils maybe employed.

By means of the rheostat the amperage'of the current may be controlled.

The contacts herein shown to which no circhit-wires are connected are provided as rests for the switch-arm a.

I claim- 1. In a rheostat, a number of resistancecoils, two series \of contacts, a movable twoarmed switch, one arm of which isinsulated from the other arm and cooperates with one series of contacts while the other arm cooper ates with the other series of contacts, and circuit-wires connecting said contacts with the resistance-coils and with one of the arms of the switch, substantially as described.

2. In a rheostat, a number of resistancecoils, two series of contacts,some of which are single contacts and-others double contacts, a movable two-armed switch, one arm of which is insulated from the other arm and cooperates'with one series of contacts while.

the other'arm cooperates with the other series of contacts, and circuit-wires connecting said contacts with the resistance-coilsand with one of the arms of the switch, substantially as described.

'name to this specification in the presence'of two subscribing witnesses.

NATHAN H: SUREN.

Witnesses:

.13. J. NOYES,

J. L.- HUTCHINSON In testimonyvwhereof' I have signed my, 

